Pendulum-type bumper for arresting metal masses descending gravity skids onto a conveyer



July 18, 1950 G. TREE 2,515,675

PENDULUM-TYPE BUMPER FOR ARRESTING METAL MASSES DESCENDING GRAVITY SKIDS ONTO A CONVEYER Filed March 28, 1946 2 Sheets-Sheet 1 590 You INVENTOR GEORGE 7??55, Q .9" g a w"! M Q :1? LEUEL bimwmeu.

fgcmo (G0 00 July 18, 1950 G. TREE PENDULUM-TYPE BUMPER FOR ARRESTING METAL MASSES 7 DESCENDING GRAVITY SKIDS ONTO A CONVEYER Filed March 28, 1946 2 Sheets-Sheet 2 25 INVENTOR t -fmr fil 50965 TREE,

Patented July 18, 1950 PENDULUM-TYPE BUMPER FOR ARREST- ING METAL MASSES DESCENDING GRlQV- ITY SKIDS ONTO A CONVEYER George Tree, Gary, Ind., assignor to Carnegie- Illinois Steel Corporation, a corporation of New Jersey Application March 28, 1946, Serial No. 657,754

11 Claims. 1

Heating furnaces for billets are usually constructed to discharge the billets sidewise by gravity down inclined skids onto a roller table which conveys the heated billets to a rolling mill.

The billet heating furnaces are, in most cases, of the continuous skid type. The billets are placed side by side on the skids at the charging end of the furnace, where the ends of the billets are lined up. A pusher machine moves the billets towards the discharge end of the furnace, and when the furnace is fully charged there is a continuous row of billets in the furnace and on the charging skids as far out as the pusher machine. This pusher machine is so designed that when the billets at the discharge end of the furnace are properly heated, one billet at a time is pushed over the discharge end of the furnace and slides down the discharge skids onto the roller table. The table is thus subject to the heavy shock of the billets descending the skids from the furnace and may be seriously damaged thereby. The billets, furthermore, frequently land askew on the table, so that additional handling and manipulation are necessary in order to center them properly before advancing them to the mill. I

Ever since rolling of billets into shapes has been practiced, trouble has been encountered as a result of the billets lodging'in the discharge opening of the furnace. The'discharge end of the furnace is at a level considerably above the roller table for carrying the heated billets to the mill, and the skids are on a slope sufficient to prevent billets from being Stopp d by friction while descending.

Although care is exercised in lining the billets up at the charging end, it occasionally happens that a billet becomes lodged in the discharge opening of the furnace. When this happens, the billet must be worked loose until it drops to the roller table. There is no mechanical means for releasing a lodged billet, and the job must therefore be done by hand using long steel bars and working directly in front of the furnace. Prior to my invention, no protection was available for the workmen, and the task of prying the billet loose was a very dangerous and unsatisfactory procedure.

In accordance with the present invention I provide a bumper suspended as a ballistic pendulum, effective to absorb the impact of the billets sliding down the skids from the furnace to the roller table and arrest them gradually, thereby minimizing the shock transmitted to the roller table.

The present invention also has for an object the provision of mechanism for raising the bumper out of obstructive position relative to the furnace opening, so as to make the discharge end of the furnace accessible to workmen when it is necessary to loosen a billet lodged therein.

A further object of the invention is to provide means for stopping the billets on the table when the bumper is in the raised position, thereby protecting the workmen.

Further objects of the invention will become apparent as the description proceeds, and the features of novelty will be set forth with particularity in the appended claims.

The invention will be understood more readily by referring to the accompanying drawings, in which:

Figure l is a front elevation of the discharge end of a billet heating furnace with the present invention applied thereto, parts of the construction being shown in section and parts being broken away to conserve space, as indicated by vertical and horizontal break lines.

Figure 2 is a sectional elevation taken on the line II--II of Figure 1.

Figure 3 is an end elevation of the bumper assembly of the present invention, showing details of the suspending mechanism partly in section along line IIIIII of Figure 1.

Figure 4 is a top plan view of the bumper ele ment of the present invention, portions of the length thereof being broken away as indicated.

Figure 5 is a detailed end elevation of the bumper element.

Referring more particularly to the drawings, reference letter A represents a billet heating furnace having a discharge opening B, and a roller table C for receiving the discharged billets. Structural I-beams D are provided for mounting a platform E.

A bumper I is suspended by a hanger at each 'end thereof. The bumper is an elongated steel casting which has a weight sufiicient to check and arrest the heaviest billets descending by gravity from the furnace A along skids indicated at 8, and to center the billets automatically on the roller table C. Preferably, the billet-engaging surface of the bumper I is beveled as indicated at 6|, in order to guide any misaligned billets into proper position on the roller table.

Duplicate suspensions are provided at each end of the bumper I and support it in the manner of a ballistic pendulum. The bumper 'I is provided with slots 9, 9 adjacent its ends to accommodate the eyes II, II of eye-bolts l3, I3. Holes l5,

l" are drilled into the ends of the bumper beyond the slots, 9, 9 for receiving pins ll, ll which extend through the eyes of eye-bolts l3, l3, thus providing pivotal mounting of the bumper on a longitudinal axis. The pins I! and I'l are retained in place by keeper plates secured to the ends of the bumper by screws 2| threaded into tapped holes 23, 23.

The suspensions for the bumper include eyebolts 25, 25. The upper and lower eye bolts are oppositely threaded in sleeve nuts 21, 21, thereby forming turn-buckles permitting adjustment of the height of the bumper relatively to the roller table C. The eye-bolts 25 and 2.": are secured to hangers 29, 29 by pins 3|, 3|, and the hangers 29, 2!! are secured to suspension links 33, 33" by pins 35, 35. The pins 3i, 35 are at right angles, as are pins 3| and 35-, and form universal joints thereby giving the bumper 1 free motion in two directions. This prevents damage to the hangers as a result of the longitudinal component of force exerted on bumper 1 by a slab descending skids 8 in skewed position thereon, i. e., at an oblique angle instead of normal to the skids.

The suspension links 33, 33 are provided with oppositely extending bearing bosses 31, 31 intermediate their ends. These bosses are engageable with pockets 39, 3!! below the level of the platform E which has openings to receive them. Chains 4|, 4| are secured to links 33, 33 by intermediate links. The chains are also secured to hoist mechanisms including sprockets 43, 43 mounted on speed reducers 45, 45 driven by motors 41. A common control system for the motors causes them to effect equal lifting and lowering movements of the bumper l. The suspensions and hoist mechanisms described provide flexible, jointed hangers for both ends of the bumper I.

Should a billet become lodged in the discharge opening of the furnace, the bumper may be easily raised out of obstructing position by operating the motors 41, 41 to permit the billet to be manuallydislodged. The, raised position of the bumper is shown in chain lines in Figure 2. In order to protect the workmen, vertical guard bars 49 are suspended from the platform E by chains 53. The bars are spaced sufficiently far apart to afford access to the interior of the furnace. They extend through holes Si in the bumper. The bumper thus slides on the bars when raised or lowered. The bars 49 are heavy enough to check the fall of the heaviest billets, even when the bumper is raised, so as to prevent injury to workmen in front of the furnace attempting to dislodge a billet, as a result of a sudden loosening and rapid descent thereof. The pins may be provided with enlarged heads 51 for attachment of eye-bolts or the like 59 to receive the suspension chains 53.

The utility of the invention will be apparent from the foregoing. It reduces the shock of the billet falling on the roller table to only a small fraction of that which the table was formerly required to absorb. The construction is rugged, and requires little attention; and the economic value in terms of savings in maintenance cost, greatly outweighs the initial cost of the installation.

For purposes of illustration only, it may be noted that in one embodiment of this invention as installed, the bumper I is 27 feet, 3 /2 inches long, and 14 inches square. The pins 43 are 2 feet, 11% inches long, and 3 inches in diameter. The holes ii are 3% inches in diameter, leaving a clearance of inch around the pins. The massiveness of the construction becomes apparent when it is recalled that steel has a weight of approximately 450 pounds per cubic foot. In the installation referred to, there are four bars 49, the outer holes 5| being 6 feet, 1% inches from each end and the two intermediate holes, 4 feet, 9% inches from the outer holes.

It will be understood that all of the foregoing dimensions are purely illustrative in character and are not intended to be limiting, as the size and dimensions employed in any installation will vary in accordance with the size of the furnace and the particular operating conditions.

As shown in the drawings, the slots 9 and 9 in the bumper l are wider than the eye-bolts I3, l3; thus when the bumper I expands on heating thereof by contact with-the hot billets, the eyebolts will work along the pins l'l, ll' as the bumper swings repeatedly, thereby maintaining their vertical position.

It will be understood that the invention is applicable to furnaces for heating metal slabs as well as those for heating billets.

I claim:

1. The combination with a billet heating furnace, of bumper means adapted to be impacted by moving heated billets being discharged from the furnace, a motor and speed reducer for each end of the bumper means, a sprocket wheel on each speed reducer, a groove in each end of the bumper means vertically below each sprocket wheel, suspension instrumentalities for the bumper means entering the said grooves at each end of the bumper means, each of the suspension instrumentalities including an eye-bolt received in the respective groove of the bumper means, the said opposite end of the eye-bolt being threaded, a second eye-bolt having an oppositely threaded end adjacent to the threaded end of the firstmentioned eye-bolt, a sleeve threadedly enclosing the threaded ends of the eye-bolts, thereby forming a turnbuckle, a hanger link for receiving the eye end of the second eye bolt, a pin pivotally connecting the said eye end of the second eye bolt to the hanger link for enabling longitudinal pendulum movement of the bumper means, a suspension link receiving the hanger link, the suspension link having a lower link portion and an upper link portion and an enlarged boss connecting these link portions, a pin pivotally connecting the hanger link to the lower link portion of the suspension link, the hanger link pin being at right angles to the pin pivotally connecting the second eye bolt to the hanger link, whereby the bumper means may swing transversely in a pendulum movement responsively to impact of a falling billet against the bumper means, a suspension chain secured to the upper link portion of the suspension link and to the sprocket wheel, and a guide for the suspension link engaged by the ends of the enlarged boss thereof preventing lateral movement thereto, the said motors being synchronized in operation to secure true vertical up-and-down movement of the bumper means responsively to operation of the motors.

2. A pendulum arrestor for a conveyor comprising an elongated bumper, hangers suspending it horizontally above the conveyor, vertical holes spaced along the bumper, and guard bars fitting loosely in said holes.

3. A pendulum arrestor for a conveyor comprising an elongated bumper, hangers suspending it horizontally above the conveyor, and vertical .guard bars spaced along the bumper and slidable relative thereto.

4. Apparatus for checking and arresting billets descending gravity discharge skids onto a conveyor comprising a bumper in the form of an elongated mass of metal disposed in substantially horizontal position above the conveyor and extending longitudinally thereof, hangers freely suspending said bumper at a level such that it will be engaged sidewise by a billet as it lands on the conveyor and be laterally displaced by the impact thereof, and hoist mechanisms for lifting said hangers to raise the bumper to an out-oi-the-way position, said hoist mechanisms each including a sprocket, driving means therefor, and a chain secured to the sprocket and one of said hangers.

5. Apparatusfor checking and arrestingbillets descending gravity discharge skids onto a conveyor comprising a bumper in the form of an elongated mass of metal disposed in substantially horizontal position above the conveyor and extending longitudinally thereof, and hangers free- Lv suspending said bumper at a level such that it will be engaged sidewise by a billet as it lands on the conveyor and be laterally displaced by the impact thereof, said bumper having vertical holes therethrough at points spaced along its length and guard bars fitting loosely in said holes.

6. The apparatus defined by claim 5 characterized by suspensions for said bars independent of the bumper.

7. In a roller conveyor adapted to receive billets descending gravity discharge skids extending laterally from the conveyor, an elongated bumper block extending along the conveyor on the side opposite said skids, and hangers suspending said block for free-swinging sidewise movement as a ballistic pendulum at a level above the conveyor such that it will be struck by the billets and lat- Number 6 erally displaced, thereby yieldingly checking and arresting the lateral sliding movement of the bi]- lets on the conveyor.

8. The apparatus defined by claim 7 characterized by said hangers including universal joints permitting longitudinal as well as lateral movement of the bumper.

9. The apparatus defined by claim 7 characterized by hoist mechanisms for lifting said hangers to raise the bumper to an out-of-the-way position.

10. The apparatus defined by claim 7 characterized by said hangers including bearing bosses and supporting pockets in which said bosses are liftably received.

11. The apparatus defined by claim 10 characterized by said bosses and pockets having cylindrical mating surfaces to permit swinging of the hangers.

GEORGE 'I'REE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date 643,143 Laug'hlin Feb. 13, 1900 732,866 Kernohan July 7, 1903 1,035,871 Gardner Aug. 20, 1912 1,127,315 Swindell -Feb. 2, 1915 1,525,880 Mueller Feb. 10, 1925 1,654,678 Brooke Jan, 3, 1928 2,086,160 Gotthardt et al July 6, 1937 FOREIGN PATENTS Number Country Date 125,827 Austria July 15, 1931 673,723 Germany Mar. 9, 1939 

